"Every car shopper should feel empowered to own their test drive and make sure that they focus on all of the factors that are most important to them," says Philip Reed, consumer advice editor at the online auto expert. "If the car doesn't look, feel or sound right in any way, then it's OK to trust your gut and walk away. The small red flags you find early on could become big waving banners down the road."

"It's a little like trying on clothes," Reed says. "People come in different sizes and shapes, and they have different tastes in what they want. The little things that you spot now could be major annoyances later, so don't discount any of your reactions."

That process starts before you get in the car, he says. Go into the experience with your eyes open, especially before you put the keys into the ignition. Here are some of the item on Reed's text-drive checklist :

Is it easy to get in and out of the new car without stooping or banging your head?

Does your body type match the pedal positions? If not, are the pedals adjustable?

Is the seat comfortable? Is it easily adjustable? Is there a lumbar support adjustment?

Is there enough room for your head, hips and legs? Remember to sit in the backseat to test it too.

How is the visibility? Check the rearview mirror and side mirrors and look for potential blind spots.

Check the trunk space and cargo area. Is the vehicle easy to load? Is there a pass-through in the trunk opening for long items?

When you do hit the open road, avoid taking phone calls and keep the radio off -- the test-drive demands your undivided attention. Pay particular attention to the car engine . Is it running smoothly? Do you hear pings or knocks? If so, those are deal-breakers.

Drive the car or truck like you would if you owned it. If you have a long commute to work, take your test drive out on the highway. If you want a tough, durable truck, take it up a hill or, better yet, a mountain to check out how the vehicle handles the added burden.